Embodiments of inventive concepts relate to an integrated circuit (IC), and more particularly, to a master device and a slave device that can communicate with each other using a single wire interface and a data processing system including the devices.
In telecommunication or computer science, serial communication is a process of transmitting data bit by bit through a communication channel or computer bus, for example. Serial communication is contrasted with parallel communication in which multiple bits are simultaneously transmitted through a link having a plurality of parallel channels. Serial communication may be used in long-haul communication and most of the computer networks, for example.
Many communication systems are designed to connect two ICs to each other on a same printed circuit board (PCB). The more pins an IC has, the more expensive the IC. In order to reduce the number of pins in a package, a serial bus is usually used for data transmission in ICs when communication speed is not important. Examples of such a low-cost serial bus include serial peripheral interface (SPI) and inter-integrated circuit (I2C).
SPI is synchronous serial communication interface usually used for short-distance communication, primarily in embedded systems. SPI may use three or four pins, which are many. In addition, there are an output driver and an input buffer connected to each of the pins, which leads to an increase of the price of chips.
I2C is a multi-master, multi-slave, single-ended, serial computer bus invented by Philips Semiconductor (now NXP Semiconductor). I2C is used for attaching low-speed peripherals to motherboards, embedded systems, and mobile telephones. I2C uses two bidirectional open-drain lines, that is, a serial data line (SDA) and a serial clock line (SCL), which are pulled up by resistors. Since I2C transmit serial data using a serial clock in order to synchronize two connected devices with each other, it consumes a lot of power. Additionally, capacitance in an I2C system may slow operations.